The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 2008
Filed:
Jan. 20, 2004
Akihiro Yasuda, Katano, JP;
Yoshiaki Komma, Hirakata, JP;
Yasuhiro Tanaka, Ashiya, JP;
Yoshiyuki Shimizu, Hirakata, JP;
Akihiro Yasuda, Katano, JP;
Yoshiaki Komma, Hirakata, JP;
Yasuhiro Tanaka, Ashiya, JP;
Yoshiyuki Shimizu, Hirakata, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An optical head is provided that increases the light utilization efficiency and that can be adapted to high-speed recording and double-layer disks. A beam-shaping lens that shapes an elliptical beam emitted from a light source into a substantially circular beam has a pair of cylindrical surfaces that are curved in the same direction. The cylindrical surface that is closer to the light source is an aspherical surface, and the cylindrical surface that is closer to the light source is a spherical surface. Thus, an optical head is obtained, with which aberrations can be kept low, even when the beam-shaping magnifying power is about a factor 2.